Semiconductor device

Abstract

A semiconductor device includes a substrate having a first side and a second side opposite to the first side; a first optical element at the first side of the substrate; and a semiconductor stack on the substrate. The semiconductor stack includes a first reflective structure; a second reflective structure; a cavity region between the first reflective structure and the second reflective structure and having a first surface and a second surface opposite to the first surface; and a confinement layer in one of the second reflective structure and the first reflective structure. The semiconductor device further includes a first electrode and a second electrode on the first surface.

What is claimed is: 
     
       1. A semiconductor device, comprising:
 a first semiconductor contact layer having a top side and a back side opposite the top side; 
 plural columnar semiconductor stack structures over the top side of the first semiconductor contact layer, and each of the columnar semiconductor stack structures includes:
 a first reflective structure; 
 a cavity region; 
 a second reflective structure; 
 a current confinement layer in the second reflective structure and having a conductive area and an insulating area surrounding the conductive area; and 
 a second semiconductor contact layer; 
 
 an insulating layer covering the columnar semiconductor stack structures and having openings formed through the insulating layer, wherein each of the openings is directly on the columnar semiconductor stack structures and at least one of the openings corresponds to at least one of the insulating areas, wherein a width of the opening is equal to or smaller than a width of the insulating area; 
 a first electrode disposed over at least portion of the back side of the first semiconductor contact layer; and 
 a second electrode disposed over at least portion of the first semiconductor contact layer. 
 
     
     
       2. The semiconductor device according to  claim 1 , wherein, in a top view, the second electrode is located at a peripheral of the semiconductor device. 
     
     
       3. The semiconductor device according to  claim 1 , wherein the insulating layer surrounds the current confinement layers of the columnar semiconductor stack structures. 
     
     
       4. The semiconductor device according to  claim 1 , wherein a width of the first semiconductor contact layer is wider than a width of the first electrode. 
     
     
       5. The semiconductor device according to  claim 1 , wherein, in a top view, the plural columnar semiconductor stack structures are substantially arranged periodically. 
     
     
       6. The semiconductor device according to  claim 1 , further comprising plural trenches over the top side of the first semiconductor contact layer,
 wherein the plural columnar semiconductor stack structures are separated from each other by the plural trenches. 
 
     
     
       7. The semiconductor device according to  claim 6 , wherein, in a top view, the plural trenches are connected. 
     
     
       8. The semiconductor device according to  claim 1 , wherein the second electrode further extends to a sidewall of at least one of the columnar semiconductor stack structures. 
     
     
       9. The semiconductor device according to  claim 8 , wherein the second electrode includes:
 a pad portion; and 
 a side portion extending from the pad portion and covering the sidewall of the columnar semiconductor stack structure, 
 wherein a width of the pad portion is wider than a width of the side portion. 
 
     
     
       10. The semiconductor device according to  claim 1 , further comprising a substrate bonded to the columnar semiconductor stack structures. 
     
     
       11. The semiconductor device according to  claim 10 , further comprising a bonding layer between the substrate and the columnar semiconductor stack structures. 
     
     
       12. The semiconductor device according to  claim 10 , wherein the substrate has protrusions thereon.